Shield for a wire harness string tie cutting tool



July 29, 1969 F. L. HILL 3,457,643

SHIELD FOR A WLHE HARNESS STRING 'lll-J CUTTING TOOL Filed Aug. 2, 1967 INVENTOR. Fawn-Jr 4. #14:.

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United States Patent 3,457,643 SHIELD FOR A WIRE HARNESS STRING TIE CUTTING TOOL Forrest L. Hill, Santa Clara, Calif. (5171 Harwood Road, San Jose, Calif. 95124) Filed Aug. 2, 1967, Ser. No. 658,312 Int. Cl. B29b 29/00 US. Cl. 30-293 3 Claims ABSTRACT OF THE DISCLOSURE A spoon-shaped, one piece, removable shield or guard having a tubular section for slidably mounting on a handle of a cutting device used for removing string ties, spot ties or lacing from a wire harness assembly.

This invention relates generally to cutting devices for removing string ties, spot ties or lacing material used in holding together wire harness assemblies, and more particularly to a removable shield or guard to be placed on the cutting device in order to eliminate the cutting device from nicking, cutting or gouging the wire insulation surrounding the electrical wires of a wire harness assembly.

In many instances, it becomes necessary to remove the string ties, spot ties or lacing material commonly used in aircraft or missile Wire harness assemblies. In order to remove these string ties, spot ties or lacing material one merely inserts a conventional cutting device, such as a jackknife, nail clipper, diagonal cutter or Exacto knife between the tie or lacing and the electrical wire of the wire harness assembly and cuts the tie or lacing. The problem which arises, however, is that because of the haste or inability of the one performing the cutting operation, accidently, the cutting device may nick, cut or gouge the insulation surrounding the electrical wires of the wire harness assembly. These nicks, cuts or gouges are in many instances overlooked when the harness assembly is inspected either because of the minuteness of the nick or cut or because of a faulty inspection operation. If a faulty wire harness assembly is used in an aircraft or missile, large amounts of money and/or lives may be lost due to a resulting fire or improper aircraft or missile operation. Even if the faulty wire harness assembly is detected in time, great expense is involved in replacing the faulty harness.

The instant invention overcomes the previously described problems encountered when removing the string ties, spot ties or lacing material used in aircraft or missile harness assemblies.

It is therefore the primary object of this invention to provide a simple, removable shield or guard adapted to be used with a cutting device in order to prevent nicking, cutting or gouging of the wire insulation surrounding the electrical wires of a wire harness assembly.

It is a further object of this invention to provide a simple, removable shield or guard for the blade of a cutting device when the cutting device is not in use.

It is still a further object of this invention to provide a simple, removable shield or guard adapted to be used with a cutting device which is economical to produce and which utilizes conventional, currently available components that lend themselves to standard mass production manufacturing techniques.

For a better understanding of the present invention, together with other and further objects thereof, reference is bad to the following description taken in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

In the drawings:

FIGURE 1 is an exploded view of the shield or guard 3,457,643 Patented July 29, 1969 according to this invention adjacent the cutting device on which it is to be mounted;

FIGURE 2 is an exploded view of the shield or guard according to this invention mounted on the cutting device and about to sever the string tie of a wire harness assembly;

FIGURE 3 is an exploded view of the shield or guard according to this invention mounted on a cutting device in the inoperative position to provide a shield or guard for the blade of the knife; and

FIGURE 4 is a modification of the shield or guard shown in FIGURES 1-3.

Referring to FIGURE 1, there is shown the shield or guard 10 of this invention about to be mounted upon a conventional cutting device such as an Exacto knife 12.

For purposes of simplicity and uniformity throughout the specification, the shield or guard 10 will be used in conjunction with an Exacto knife (hereinafter described). However, it should be realized that this is not to be construed as a limitation upon the instant invention, but merely illustrative of a conventional cutting device upon which the shield or guard 10 of this invention can be mounted.

The Exacto knife 12 which is of conventional construction usually comprises a blade 14 which has a cutting edge 16 thereon. The blade 14 is held in place by having one end thereof inserted in slot 18. A conventional knurled fastening means 20 is mounted on the Exacto knife 12 around slot 18 in order to hold the blade 14 in a fixed position. There is a groove 22 located adjacent the knurled fastening means 20 in the handle 24 of the knife 12. This groove 22 which forms no part of the instant invention, may, however, be used in conjunction with a modification of this invention to be described hereinafter.

Still referring to FIGURE 1, there is also shown shield or guard 10 of this invention. The shield or guard 10 is fabricated of any suitable material such as a piece of aluminum or rubber tubing which is commonly used in aircraft and aerospace industries. This tubing has a grinding or other suitable shaping operation performed on it in order to shape it into its desired configuration. After the grinding or other suitable shaping operation is performed, the tube takes the desired form shown in the drawings. That is, the shield 10 now comprises a spoon-shaped section 26 and a tubular section 28 having at least two slits 29 therein. The slits 29 give the tubular section 28 the desired amount of resiliency necessary for mounting it upon knife 12. Furthermore, the slits 29 permit the shield or guard 10 to be used with cutting devices of a variety of sizes. The spoon-shaped section 26 is made up of a diagonal edge 30 which extends into an edge which has two upstanding elements 32 thereon. This spoon-shaped section with elements 32 thereon performs two functions: (1) it acts as a guide when the cutting device 12 is inserted between two wires 34 and a tie or lacing 36 of a wire harness assembly 38 (shown in FIGURE 2), and (2) it acts as a shield for the cutting edge 16 of blade 14 when the cutting device 12 is not in use (shown in FIGURE 3). In use the shield 22 is mounted upon a suitable cutting device such as an Exacto knife 12 with the spoon-shaped section 26 extending slightly beyond the tip of blade 14. The cutting device 12 is then slipped between the electrical wires 34 and string tie 36 of wire harness assembly 38. The shield or guard 10 prevents the cutting edge 16 of the blade 14 from gouging or nicking the insulation 40 on the electrical wires 34 when removing the string tie or lacing material 36 from the wire harness assembly 38. As a safety feature and also in order to protect the cutting edge 16 of blade 14 the shield or guard 10 can be rotated on the knife 12 to the position shown in FIGURE 3.

Referring now to FIGURE 4, there is'shown a slight V v Although "the invention has been described with refermodification of the, shield or guardw ltl and it will therefofe hereinafter be designated as shield or guard 42. The shield or guard 42 is substantially identical in structure to .shield or-guard 10. It comprises of spoon-shaped section 26, tubular section 28 and slits 29. Shield or guard 42 also has diagonal edge 30 which extends into an edge containing upstanding elements 32. In addition to the above eleing means 44 such as punch indentations located in the tubular section 28 and adapted to ride in groove 22 of the knife 12. The holding means 44 does not constitute a permanent holding means but ,in conjunction with slits 29 'me'nts,"shield or guard 42 further comprises suitable holdprovides a resilient holding means which may slip into and out of groove 22 upon the application of a force to shield or guard 42 whenever it is necessary to mount or to remove the shield or guard 42 from the knife 12.

The shield or guard 42 may also be rotated in the manner shield or guard 10 is rotated, with the holding means 44 riding in groove 22 during this rotation, The fact that the shield or guard 10 or 42 of the instant invention is removable is not to be construed as a material limitation since the shield or guard may form a permanent part of the cutting device, if so desired.

The operation of both shield 10 and 42 will now be described using as an example shield 10 in conjunction with knife 12. It should be realized that these shields 10 and 42 may be readily interchanged.

.,ence.to, particular embodiments, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.

I claim:

1. In a cutting device for removing the string ties surrounding the insulated wires of a Wire harness assembly having a handle, a blade having a cutting edge mounted at one end of said handle'and a groove in said handle adjacent said blade, the improvement being a shield rotatably mounted on said handle for movement to at least two positions, said shield comprising a tubular section having holding means for engaging said groove, a spoon-shaped section extending from one end of said tubular section to slightly forward of the tip of said blade, a pair of upstanding elements on said spoon-shaped section partially surrounding said blade, said shield exposing said cutting edge in one of said positions and covering said cutting edge in the other of said positions whereby said shield in said one position permits access to the cutting edge while preventing said tip from nicking said insulation of said wires of 'said wire harness when removing said string ties therefrom.

The shield 10 is forced on the knife 12 by pushing tubular section 28 onto handle 24 until the spoon-shaped section 26 of the shield or guard 10 Extends slightly beyond the tip of the blade 14. Because of the force fit between tubular section 28 and handle 24 the shield 10 is held in place. The knife 12 with the shield or guard 10 thereon is now slipped between the electrical wires 34 and string tie or lacing 36 of wire harness assembly 38 (shown in FIGURE 2). With the shield or guard 10 in place, the cutting edge 16 of the blade 14 severs only the string tie or lacing 36 and does not gouge the insulation 40 on the electrical wires 34 which so commonly occurs without shield or guard 10. After using the knife 12 the shield or guard 10 may be removed from the knife 12 or rotated on the knife to protect the blade 14 and the user from damage or injury.

2. In a cutting device-as defined in claim 1 wherein said holding means comprises punched indentations in said tubular section.

3. In a cutting device as defined in claim 2 wherein said shield made of a single piece of aluminum tubing and said tubular section has at least two slits therein.

References Cited UNITED STATES PATENTS 1,268,997 6/1918 Pruett -294 1,274,966 8/1918 Wentz a- 30294 1,318,346 10/1919 Berthelsen 30-294 2,288,555 6/1942 Jacques 30151 2,336,779 12/1943 Creasy 30-151 X 2,348,429 5/1944 Walker 30-287 X ROBERT C. RIORDON, Primary Examiner US. Cl. X.R. 30-294 

